Polarized electromagnetic relay



Jan; 27;"1948. o. s. FIELD 2,435,001

POLARIZED ELECTROMAGNETIC RELAY Original Filed Oct. 14, 1940 Bnnentor '(Zwa/u 5 $4M,

M M M (Ittomeg Patented Jan. 27, 1948 2,435, 01. .POLARIZED ELECTROMAGNETIC RELAY Oscar S.

General Original application Oct 361,060, new Patent 22, 1945. 1'7, 1945,

Field, Rochester, N.

Railway Signal Company,

Y., assignor to R chester,

ober 14, 1940, Serial N0.

N0. 2,376,534, dated May' Divided and Serial No. 588,749

this application April 3 Claims. (Cl. 175-9335) This invention relates to relays and/or electroresponsive devices which will be actuated only if current of the proper character and polarity flows simultaneously in two circuit portions. This application is a division of my prior application Ser. No. 361,060, filed October 14, 1940, which has resulted in a Patent No. 2,376,534, dated May 22, 1945.

Multiple winding relays and electromagnets employing two windings such as devices of the dynamometer type are well known but by reason of their high reluctance w on no iron is used therein are very inefficient, If such electrom gnets o rel ys are provided with a considerable amount of soft ron in either or bo of their w ndin s to improve their effl e cy there is a. danger of actuation of the electromagnet or relay in response to the ener zation of on y ne of their windings to an excessive extent.

In view of the foregoing it is proposed in accordance with the present invention to provide an electromagnet for an electr c-responsive device employing a multiple closed magnetic core structure so arranged that each of the two closed cores serves as a very effective magnetic shunt for the other core and to provide each such closed core with its individual winding.

Another feature of the present invention follows from the fact that if the relative polarity of one of the two circuits or circuit portions for energizing the two windings is opposite from what was intended, the electroeresponsive device will not respond, and thus the structure may be used as a polar relay or polar electromagnet.

As another object of the present invention it is proposed to employ a full-wave rectifier when the electromagnetic structure is to be used as a direct current polarity responsive device by having one of the two windings energized from the rectifier the input terminals of which receive their energy from the circuit for energizing the other winding.

Other objects, purposes and characteristic features of the invention will in part be pointed out in'the specification hereinafter and will in part be obvious from the accompanying drawing which shows the invention applied for performing a polarity responsive function in which the device derives all of its energizing current from a single pair of inlet wires.

In the drawing, corresponding to Fig. 22 of the parent application, the electro-responsive structure embodying the present invention is shown at the left, whereas the electr c-responsive structure shown at the right and including the coil I60 is merely shown incidentally and is shown connected in series with the winding I50 and may, if desired, be disregarded or assumed omitted from the disclosure. When omitted it is merely removed from the circuit of coil I50.

As shown the core structure of the electroresponsive device comprises a closed U-shaped magnetic circuit portion of soft iron including a back yoke I51 and legs I5I and I52 which terminate in pole pieces I53 and I54, respectively, and which core structure is shunted by a soft iron bridge I55. This structure therefore includes a closed magnetic circuit comprising the back yoke I51 and the bridge I55. with portions of the legs HI and I52 in series. An armature 6 preferably pivoted at one end, as shown, is in magnetic cooperative relationship with the pole pieces I53 and I54 by bridging the same as shown, This armature G is so spaced from the pole pieces I53 and I54 and is provided with such residual pin or residual stop structure that the relay will function only if magnetomotive forces of proper value and polarity are set up in both core portions I55 and I51. For this purpose windings or coils I48, I49 and I50 have been provided. The coil or winding I50 supplies the magnetomotive force in the back yoke I51, whereas the coil or winding I48-rl49, which for convenience has been split into two parts, supplies the magnetomotive force in the magnetic bridge I55. The winding I48-I49 could obviously be a single winding it having been shown split into two parts to protect the full-wave rectifier I58 against lighting and to bring this rectifier and the windings I50 and I60 energized thereby to an intermediate potential with respect to the inlet wires l6I and IE2. The armature G may be provided with a movable contact I when the device is to be used as a relay and may in other instances be used to operate other devices, such for instance, as a signal spectacle as shown in the parent application.

If the minus terminal of a direct current source is connected to the wire IN and the plus terminal of such current source is connected to the wire I62, as conventionally shown, the closure of the circuit as by the depression of push button I56 will cause current to flow from the plus terminal of said source through coil I48, the lower right-hand rectifying element of rectifier I58, coil I60, coil I50, upper lefthand rectifying element of rectifier I58, coil I49, push button I56, wire "H, to the minus terminal of :the source. The flow of this current will cause magnetomotive forces to be set up as terminal of such source is connected to the wire 7' I62 depression of the push button I56 will cause current to flow through a circuit in a direction which may be traced from terminal wire I 6 I push button I56, coil I49, u per right-hand rectifying element of rectifier I 58, coil I50, coil larger than the pick-up If now, on the 7 I50, lower left-hand rectifying element of rectifier I58, coil I48. wire I62, to the terminal of the source Obviously, the direction of the magnetomotive force in the magnetic bridge I55 will be in the opposite direction as indicated by the solid arrows whereas the direction of the magnetomotive force in the back yoke I51 and in the coil I60 will remain in the same direction as heretofore, namely, in the direction of the solid arrow so that in this case the magnetomotive forces set up in the back yoke I 51 and the bridge I55 are in the same direction in the closed magnetic loop comprising these core portions I55 and I51 in series with portions of the legs I SI and I52. The ma netomotive force impressed across the poles I53 and I54 is therefore substantially zero and the armature G will not pick up.

In a structure of the type just described it is important that the armature G should not pick up as a result of the breaking of the circuit including the coils I50 and I60, for instance. If this should occur the resistance of the rectifier I58 would of course become very high, its out-put circuit being open, and for this reason among other reasons, less than normal current would flow in the coils I48 and I49 and the armature G would not pick up. Let us now assume, for the purpose of discussion only, that the coil I50 becomes short-circuited so that the resistance of the rectifier I58 is not increased and again in this case the armature G will not pick up because the magnetomotive force set up in the bridge I 55 is shunted away from the armature G by the back yoke I57. In fact, the spaced and structural relationship between the armature G and the core structure I5I, I52, I55, I51 is such that if double or even triple current is applied to either of the coils I48-I49 or I 50 the armature G will not pick up by reason of the fact that the mag netomotive force produced by such coil is sub stantially entirely shunted away by the shunting effect of the core portion on which the other coil is wound.

The structure described may of course exclude the electromagnet including coil I60, in which event the number of turns and size of wire employed in coil I50 is so chosen that the ampere turns flowin around back yoke I 51 is substantially the same as it was prior to the removal of coil I50. Also in practice the ampere turns of both coils I48-I49 and I50 are preferably approximately the same.

What I claim is:

1. An electro-responsive device comprising, a soft iron core having a closed magnetic circuit divided into two magnetic core portions in series, a pole piece projecting from each of the two junctions of said magnetic core portions, a winding on each' of said'magnetic core portions, a fullwave rectifier deriving its energy from the circuit of one of said windings and applying its out-put energy to the other of said windings, whereby if said one winding is energized by direct current of either polarity the said other winding is always energized by current of one polarity, and an armature-arranged to be in bridging relationship with respect to said pole pieces, whereby if said wave rectifier having its in-put leads included in series in the circuit of one of said windings and having its out-put leads connected to the other of said windings, whereby if said one winding is energized by direct current of either polarity the said other winding is always energized by current of one polarity, and an armature arranged to bridge said pole pieces, whereby it said one winding is energized by direct current of one polarity said armature is attracted and if energized by current of the reverse polarity said armature remains retracted.

3; In an electro-magnetic device, an operating electro-magnetic structure having an operating winding, a pivoted armature disposed to be attracted through an airgap from a biased retracted position by the energization of said operating winding, a, shunting electro-magnetic structure having a control winding, said shunting electromagnetic structure being disposed so as to form a magnetic circuit of relatively low reluctance REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Date Number Name 584,417 Scribner June 15, 1897 1,693,135 Cardwell Nov. 27, 1928 1,897,045 Fry Feb. 14, 1933 2,089,448 Swanson Aug. 10, 1937 2,376,534 Field May 22, 1945 

